const cfg = require('./config.js'),
    isLetter = c => (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');

function CssHandler(tagStyle) {
    var styles = Object.assign(Object.create(null), cfg.userAgentStyles);
    for (var item in tagStyle)
        styles[item] = (styles[item] ? styles[item] + ';' : '') + tagStyle[item];
    this.styles = styles;
}
CssHandler.prototype.getStyle = function(data) {
    this.styles = new parser(data, this.styles).parse();
}
CssHandler.prototype.match = function(name, attrs) {
    var tmp, matched = (tmp = this.styles[name]) ? tmp + ';' : '';
    if (attrs.class) {
        var items = attrs.class.split(' ');
        for (var i = 0, item; item = items[i]; i++)
            if (tmp = this.styles['.' + item])
                matched += tmp + ';';
    }
    if (tmp = this.styles['#' + attrs.id])
        matched += tmp + ';';
    return matched;
}
module.exports = CssHandler;

function parser(data, init) {
    this.data = data;
    this.floor = 0;
    this.i = 0;
    this.list = [];
    this.res = init;
    this.state = this.Space;
}
parser.prototype.parse = function() {
    for (var c; c = this.data[this.i]; this.i++)
        this.state(c);
    return this.res;
}
parser.prototype.section = function() {
    return this.data.substring(this.start, this.i);
}
// 状态机
parser.prototype.Space = function(c) {
    if (c == '.' || c == '#' || isLetter(c)) {
        this.start = this.i;
        this.state = this.Name;
    } else if (c == '/' && this.data[this.i + 1] == '*')
        this.Comment();
    else if (!cfg.blankChar[c] && c != ';')
        this.state = this.Ignore;
}
parser.prototype.Comment = function() {
    this.i = this.data.indexOf('*/', this.i) + 1;
    if (!this.i) this.i = this.data.length;
    this.state = this.Space;
}
parser.prototype.Ignore = function(c) {
    if (c == '{') this.floor++;
    else if (c == '}' && !--this.floor) {
        this.list = [];
        this.state = this.Space;
    }
}
parser.prototype.Name = function(c) {
    if (cfg.blankChar[c]) {
        this.list.push(this.section());
        this.state = this.NameSpace;
    } else if (c == '{') {
        this.list.push(this.section());
        this.Content();
    } else if (c == ',') {
        this.list.push(this.section());
        this.Comma();
    } else if (!isLetter(c) && (c < '0' || c > '9') && c != '-' && c != '_')
        this.state = this.Ignore;
}
parser.prototype.NameSpace = function(c) {
    if (c == '{') this.Content();
    else if (c == ',') this.Comma();
    else if (!cfg.blankChar[c]) this.state = this.Ignore;
}
parser.prototype.Comma = function() {
    while (cfg.blankChar[this.data[++this.i]]);
    if (this.data[this.i] == '{') this.Content();
    else {
        this.start = this.i--;
        this.state = this.Name;
    }
}
parser.prototype.Content = function() {
    this.start = ++this.i;
    if ((this.i = this.data.indexOf('}', this.i)) == -1) this.i = this.data.length;
    var content = this.section();
    for (var i = 0, item; item = this.list[i++];)
        if (this.res[item]) this.res[item] += ';' + content;
        else this.res[item] = content;
    this.list = [];
    this.state = this.Space;
}
